This invention relates to a silver halide color photographic light-sensitive element and more particularly to a silver halide color photographic light-sensitive element capable of providing a magenta color image in which discoloration scarcely occurs even if the image is exposed to light for a long period of time.
As is well known in the art, when a silver halide color photographic element is color-developed, an oxidized aromatic primary amine color developing agent reacts with a coupler agent to form a dye, such as an indophenol, indoaniline, indamine, azomethine, phenoxazine, phenazine compound, or the like, resulting in the formation of a color image.
In this type of system, the subtractive color process is usually employed for color reproduction, and silver halide emulsions selectively sensitive to blue, green, and red are used in combination with complementary color (yellow, magenta, and cyan, respectively) image-forming agents. For formation of a yellow color image, for example, acylacetanilide or a dibenzoylmethane coupler is used; for formation of a magenta color image, a pyrazolone, pyrazolobenzimidazole, cyanoacetophenone or imidazolone coupler is used; and for formation of a cyan color image, a phenol coupler, e.g., phenols and naphthols, is typically used.
However, such color images tend to become discolored when it is exposed to high intensity light. In particular, the discoloration of the magenta color image by exposure to light proves a serious hindrance to the stable storage of color photographs for a long period of time.
Certain attempts to make the magenta color image obtained using 3-anilino-5-pyrazolones light fast have heretofore been made. For example, (1) an ultraviolet ray absorbing agent to protect the color image from ultraviolet rays may be incorporated into the color photographic element; (2) the dye per se may be made more light fast by suitably selecting the structure of the coupler; and (3) a discoloration preventing agent may be incorporated to prevent the decomposition of the dye caused by light.
As such discoloration preventing agents, substituted hydroquinones, .alpha.-tocophenols, 6-hydroxycumarones, 5-hydroxycumaranes, 6,6'-dihydroxy-4,4,4',4'-tetramethyl-bis-2,2'-spirocumarone derivatives, sterically-hindered phenol compounds, alkoxyphenols, etc., are known. Recently, compounds prepared by replacing the hydroxy group of the above-described hydroquinone derivatives, phenol derivatives and cumarone derivatives, e.g., tocophenol, by an alkoxy group, an acyloxy group, etc., have been proposed.
These compounds are somewhat effective in preventing the discoloration of the magenta color image. However, they suffer the disadvantages that the effect of preventing the discoloration is small and that even though they are somewhat effective in preventing the discoloration, they deteriorate the hue, produce fog, cause insufficient dispersion, and produce crystals. Thus, there is a continuing color image stabilizers exhibiting generally excellent effects for photography.
A method of stabilizing a dye by using a metal complex is disclosed in Japanese Patent Application (OPI) No. 87649/75 (The term "OPI" as used herein refers to a "published unexamined Japanese patent application") and Research Disclosure, 15162 (1976). Metal complexes as disclosed therein, however, are not high in the effect of preventing the discoloration per se, and furthermore are not high in the solubility in a solvent as a photographic additive. It is, therefore, not possible to add the metal complexes in amounts sufficient to exhibit the effect of preventing discoloration. Moreover, since the metal complexes per se are highly colored, addition of a large amount of such complexes exerts adverse influences on the hue and purity of the image.
Although the technique to make light fast yellow color images and cyan color images has been substantially achieved by long and continuing studies, light fastness of magenta color images is not still sufficient. Thus, it has greatly been desired to improve the light fastness of magenta color images in order to maintain a good balance of light fastness.